Division of Ecology and Evolution, Stiftung Tieraerztliche Hochschule Hannover, Hannover, Germany.
PLoS One. 2007 Aug 1;2(8):e694. doi: 10.1371/journal.pone.0000694.
Regulatory genes of the Antp class have been a major factor for the invention and radiation of animal bauplans. One of the most diverse animal phyla are the Cnidaria, which are close to the root of metazoan life and which often appear in two distinct generations and a remarkable variety of body forms. Hox-like genes have been known to be involved in axial patterning in the Cnidaria and have been suspected to play roles in the genetic control of many of the observed bauplan changes. Unfortunately RNAi mediated gene silencing studies have not been satisfactory for marine invertebrate organisms thus far. No direct evidence supporting Hox-like gene induced bauplan changes in cnidarians have been documented as of yet. Herein, we report a protocol for RNAi transfection of marine invertebrates and demonstrate that knock downs of Hox-like genes in Cnidaria create substantial bauplan alterations, including the formation of multiple oral poles ("heads") by Cnox-2 and Cnox-3 inhibition, deformation of the main body axis by Cnox-5 inhibition and duplication of tentacles by Cnox-1 inhibition. All phenotypes observed in the course of the RNAi studies were identical to those obtained by morpholino antisense oligo experiments and are reminiscent of macroevolutionary bauplan changes. The reported protocol will allow routine RNAi studies in marine invertebrates to be established.
Antp 类调控基因是动物胚形辐射和发明的主要因素。刺胞动物门是最具多样性的动物门之一，它们接近后生动物生命的根源，通常出现两代，身体形态多样。已知同源盒样基因参与刺胞动物的轴向模式形成，并被怀疑在许多观察到的胚形变化的遗传控制中发挥作用。不幸的是，到目前为止，RNAi 介导的基因沉默研究对于海洋无脊椎动物生物并不令人满意。迄今为止，还没有记录到支持同源盒样基因诱导刺胞动物胚形变化的直接证据。本文报道了一种海洋无脊椎动物的 RNAi 转染方案，并证明了在刺胞动物中抑制同源盒样基因会导致显著的胚形改变，包括 Cnox-2 和 Cnox-3 抑制导致多个口极（“头”）的形成、Cnox-5 抑制导致主体轴变形和 Cnox-1 抑制导致触手复制。在 RNAi 研究过程中观察到的所有表型都与形态发生素反义寡核苷酸实验获得的表型相同，使人联想到宏观进化胚形变化。所报道的方案将允许在海洋无脊椎动物中建立常规的 RNAi 研究。
